human909 wrote:
Thoglette wrote:find_bruce. I'll buy your first paragraph. But the second is not supported by the evidence.
Are you sure about that? Do you have evidence to the contrary?
Yes, the speed=>fatalities is well established (as
reported in SMH 2014)
I'll have to dig a little deeper for the "speed=>loss of situational awareness" but IIRC somewhere I've got a study from Sweden which was trying to measure the effectiveness of hi-viz and ended up showing that as speed increased motorists started to simply fail to see the cyclists.
I spent a fair bit of the noughties working with systems relating to operator cognitive load (industrial control systems etc) and fatigue management so, for me, it's now "common sense". I've probably got some papers still stashed at home but
https://scholar.google.com will likely be faster than me.
human909 wrote:The vast majority of collisions with pedestrians and cyclists occur at intersections when motor vehicles are turning. This would generally imply 'speeding' is not a factor. .... (Inattention and "I think there is enough space" are common causes.)
There's two forms of inattention: boredom; and fixation & overload. Boredom is "caused" by road overdesign: long, straight stretches of featureless road. Might as well re-program the radio or have lunch or call Bruce. This is a design problem and (short of bumping up the speed limit), really needs to be addressed by separation of peds and cyclists from fast, straight traffic. Of course the AS/NZS standards don't call for that when building 80kph+ roads, despite the minimal incremental cost. As I said, a design problem.
Fixation and overload are separate spots on the same spectrum. Indeed fixation is an attempt to cope with overload and is likely the major cause of SMIDSY for peds and cyclists. I assume everyone's seen Daniel Simon's gorilla vs basketball pass (vs everything else) video before?
Motorists in "difficult" traffic conditions are going to start to fixate on MVs and start to miss the peds stepping off the curb or cyclists already in the roundabout (that's already happened to me several times this month). As for checking blind spots,
forgettaboutit. This is exacerbated with drivers who have to concentrate on the task of actually driving: new drivers; people in hire/new cars; people who rarely drive; or those in unfamiliar territory.
No-one should be surprised to hear that the answer to cognitive overload is to SLOW DOWN. Yes, there's a real problem (especially in 2GB land) with certain drivers who believe that "roads are for cars" and it's not their fault if peds get killed. However, most drivers don't want to hit pedestrians but they're "in a hurry" or have to "keep up with the traffic". So they drive faster than their mental capacity allows (that's not meant as a dig
).
I'm short linkable cites at the moment but
six seconds with google scholar provides a far bit of reading (adding "pedestrian" finds some more interesting stuff)
PS.
Someone's going to take me to task for using speeding and speed interchangably. I have two defences: one is that a large proportion of suburban drivers are speeding all the time (in WA, NT, Vic. QLD and NSW, in my experience). That is, the speed limit is treated as, at best, a recommended average if not a minimum speed. Secondly, there's an argument that speed limits are arbitrary and fixating on them is ignoring the real problem, which is "bad driving". But when was the last time some one got a ticket for driving too quickly yet still under the speed limit? Indeed the complaint is that "drivers will fixate on their speed". Why not set one'starget speed a few kph
below the limit?
Never!
And we're back to defence one.